Mitsubishi Denki Kabushiki Kaisha

Nec Corporation

Takao Morimoto

Tatsunori Fujiwara

Shigeki Asai

Takayuki Niioka

Yasuyuki Nakanishi

Masao Sato

Takashi Matsuda

Kenichirou Minemoto

Masaki Kobayashi

Kenichi Maruhashi

Keiichi Ohata

Yasuhiro Hamada

Kenji Sato

Masaharu Ito

Yoshihiro Sasaki

Tomoaki Kato

Kazutoshi Taniguchi

Shinya Sudo

Takashi Kuzuu

Shuya Kishimoto

Takaharu Eguchi

Yoshiharu Muroya

Masaharu Itou

Shuuya Kishimoto

The invention provides a semiconductor optical modulator including a two-step mesa optical waveguide having a first clad layer (); a mesa-like core layer () formed over the first clad layer (); and a second clad layer () formed into a mesa shape over the core layer (), and having a mesa width smaller than that of the core layer (). The two-step mesa optical waveguide includes a multi-mode optical waveguide region to which an electric field is applied or into which an electric current is injected, and a single-mode optical waveguide region to which the electric field is not applied and into which the electric current is not injected. When the mesa width of the core layer in the multi-mode optical waveguide region is defined as W, and the mesa width of the core layer in the single-mode optical waveguide region is defined as W, W&#x3e;Wis satisfied.

Semiconductor optical modulator, semiconductor optical integrated device, and method of manufacturing the same

Provided is a semiconductor device with a high breakdown voltage yield of a bipolar transistor and a high bandwidth and quantum efficiency of a light receiving element. An optical semiconductor device includes monolithically integrated transistor and light receiving element. The light receiving element includes a p-type semiconductor layer, an n-type epitaxial layer formed on the p-type semiconductor layer, and an n-type diffusion layer formed on the n-type epitaxial layer. An n-type impurity concentration of the n-type diffusion layer is 3&#xd7;10cmor less at a depth of 0.12 &#x3bc;m or more below a surface of the n-type diffusion layer, 1&#xd7;10cmor more at a depth of 0.4 &#x3bc;m or less below the surface, and 1&#xd7;10cmor less at a depth of 0.8 &#x3bc;m or more below the surface, and an interface between the p-type semiconductor layer and the n-type epitaxial layer is located at a depth of 0.9 &#x3bc;m to 1.5 &#x3bc;m below the surface.

Semiconductor device and method of manufacturing the same

The present invention intends to improve communication efficiency between two communication apparatuses each engaged in the communication by full duplex communication method by using a surplus band of the one to transmission band of the other. A first bandwidth required by a first communication apparatus (A) at data transmission and a second bandwidth required by a second communication apparatus (B) at data transmission are presumed. Next, the first bandwidth presumed as mentioned is compared to a first bandwidth used which the first communication apparatus (A) currently uses and at the same time, the second bandwidth presumed as mentioned is compared to a second bandwidth used which the second communication apparatus (B) currently uses. The first bandwidth and the second bandwidth are then adjusted, and a third bandwidth which the first communication apparatus (A) uses at data transmission and a fourth bandwidth which the second communication apparatus (B) uses are determined.

Band control method and communication apparatus

A balun circuit includes a first CPW line, a second CPW line, and a third CPW linethat serve as signal input/output ports; a first CPS linethat is a differential transmission line, the first CPS linerelaying the first CPW lineto the second CPW line; a second CPS linethat is a differential transmission line, the second CPS linerelaying the first CPW lineto the third CPW line; and at least one connection section that connects grounded conductors of each of the first CPW line, the second CPW line, and the third CPW line

Balun circuit and integrated circuit device

A supplementary roller is disposed on the end of a disk guiding section so that the outer face of the cylindrical shaped section of the supplementary roller is placed on the conveying roller side by the protruding section formed on disk guiding section

Disk unit with rollers

A disk device is provided with an MD carrying mechanism which uptakes an MD , places the MD on a turntable, and performs the ejection of the MD from the turntable by the displacement of the holder drawing lever which forms part of a linking mechanism when the cartridge of the MD is inserted into an MD holder. The disk device also comprises a clamp lever avoidance mechanism which refuges the clamp lever , which is used for clamping the CD , to a position which does not interfere with the uptake and ejection of the MD during uptake and ejection of the MD by the MD carrying mechanism.

Disk device for disks having different sizes

A disk device is comprised of a CD conveying mechanism which performs the uptake and ejection of CDs by a conveying roller . An MD conveying mechanism drives a clamp lever rotating mechanism which performs the refuge of the clamp lever from an initial position and the return of the clamp lever to an initial position by being driven by a CD loading drive motor. A CD is clamped by a clamp mechanism when the CD is loaded onto a fixed position in the device and directed to a turntable. When an MD is loaded or ejected, the MD conveying mechanism drives the refuge or return of the clamp lever . The placement of an MD on a turntable is performed by an MD placing mechanism which is driven as a result of an MD being taken up to a fixed position in the device.

Disk device for loading and ejecting disks

In exposing a diffraction grating pattern on a resist, the diffraction grating pattern is exposed via EB on an active region and the adjacent thereto only and the region which is not exposed via EB is exposed via Deep UV light so that the resist may be left on the active region and the adjacent thereto only after the exposed resist is developed according to the process of forming a diffraction grating for a distributed feedback semiconductor laser of the present invention. In addition, the resist-coated area can be gradually reduced from the resist existing area to the non-resist existing area and the average height of the substrate on which said diffraction grating is formed can be gradually changed on the diffraction grating forming region and non-diffraction grating forming region which results in preventing the crystallinity of a semiconductor layer on the substrate from being deteriorated. This enables formation of an excellent crystallinity semiconductor layer on the substrate on which the diffraction grating is locally formed.

Method for manufacturing diffraction grating and method for manufacturing semiconductor laser

A disk device comprises first and second disk selection projections which regulate an angle of the disk conveyed to a small or large disk positioning recess on the basis of an outer radius of the disk. The first and second disk selection projections have tapered faces provided at fixed intervals on a disk guiding face facing the conveying roller The disk device further comprises steps for positioning the small disk or the large disk having an angle regulated in accordance with the outer radius to the small disk positioning recess or to the large disk positioning recess

Disk device for disks of different sizes

A disk device is comprised of a feed roller displacement mechanism which displaces a position of a feed roller to a position lower than a position when a CD is inserted. When a CD is ejected from the turntable, the position of the feed roller displaced downwardly is returned to an initial insertion position.

Disk device

A disk holding device supports a disk as a recording medium. The disk holding device includes a motor rotating shaft ( ) protruding upward from a driving motor ( ); an upper ( ) and lower bearing ( ) which are disposed at an upper portion and a lower portion of the driving motor and rotatably support the motor rotating shaft; a thrust bearing ( ) for supporting a bottom of the motor rotating shaft; a turntable ( ) which is fitted coaxially to the motor rotating shaft at the protruding side of the motor rotating shaft mounting a disk ( ); a disk clamping body ( ) including, at its lower part, a disk clamping portion ( ) for clamping the disk in the same axial direction as the motor rotating shaft and, its upper part, a spherical protruding portion ( ) in the same axial direction as the motor rotating shaft; a motor fixing mount ( ) to which the driving motor is fixed; a tension spring ( ) bridged between the motor fixing mount and a pressing arm described later; and the pressing arm ( ) one end of which is pivotally attached to the motor fixing mount, the other end of which includes an inclined portion ( ) with an inclination angle of 95&deg; to 104&deg; with respect to an axis of the motor rotating shaft, and which presses the spherical protruding portion of the disk clamping body in an axial direction of the motor rotating shaft and in a direction perpendicular to the motor rotating shaft.

Disk supporting device

The present invention is provided with a reinforcing base section which is secured to and engages with an independent lateral plate which is formed on a corner section of a chassis and a damper which is integrated with said reinforcing base section and which absorbs vibrations of said disk playing unit. In this way, it is possible to reinforce in a simple way a corner section of a chassis which is formed by progressive die molding. In addition, since the damper section is disposed simultaneously by the fixation of the reinforcing base section to the chassis , it is possible to improve the efficiency of the assembly operation at each stage, reduce the number of components and reduce costs.

Corner part reinforcing device of disc device chassis

The bearing device comprises a bearing,, a washer,and a coupling piece,that couples the bearing,to the washer,and/or separates itself from the washer,and the bearing,by a pressure force applied thereto, wherein the bearing, the washer and the coupling piece are integrally formed with each other, and the base flap,is formed with a projection,. Due to this construction, an operator can easily hold the bearing,and the washer,as one component, and as the coupling piece,can be readily removed by the projection,, a working efficiency for installing this device can be drastically improved, and the automated mounting operation thereof can also be easily implemented.

Bearing device

A tape player is provided to simplify a mechanical part, eliminate parts, and provide efficient assembly of the mechanical part and a more compact apparatus. The tape player includes pins respectively moving in four different grooves provided in one disk-like cam, and a lever in conjunction with the movement of the pins to use movement of the lever so as to perform a cassette tape carry in/out operation, a head base moving operation, a playback running direction switching operation, and a selective operation to transfer driving force to a reel rest during fast forward.

Tape player having a cam and a mode detecting gear

A tape player is provided to simplify a mechanical part, eliminate parts, and provide efficient assembly of the mechanical part and a more compact apparatus. The tape player includes pins respectively moving in four different grooves provided in one disk-like cam, and a lever in conjunction with the movement of the pins to use movement of the lever so as to perform a cassette tape carry in/out operation, a head base moving operation, a playback running direction switching operation, and a selective operation to transfer driving force to a reel rest during fast forward. A half blanking is provided for a periphery of a hole portion in the main base to prevent a gear portion of a reel rest from contacting the main base.

Growing community of inventors

Tokyo, Japan

Takao Morimoto